1. Field of the Invention
The present invention relates to a blade changing tool suitable for use in mounting a hub blade having a circular hub to a spindle of a cutting device or in demounting the hub blade from the spindle.
2. Description of the Related Art
In a dicing device or the like, a cutting blade having a thin cutting edge is mounted to a blade mount provided at the front end of a spindle, wherein the cutting blade is used to cut a silicon wafer on which ICs or LSIs are formed, a resin board, a glass plate, etc., thereby separating individual LSI chips or electronic devices. The cutting blade most used in the dicing device at present is called a hub blade, which is composed of a circular base having a circular hub and a cutting edge formed along the outer circumference of the circular base by electroforming of diamond abrasive grains. If a very brittle cutting blade having a thickness of about 20 to 30 μm is directly held by an operator's hand, there is a possibility that the cutting blade may be easily damaged. To cope with this problem, the cutting edge of the hub blade is formed along the outer circumference of the circular base having the circular hub to be held by the fingers.
However, there is a case that the circular hub of the circular base is narrow in width or the fingers are necessarily put on the circular hub near the cutting edge. As a result, there is a possibility that the cutting edge may be erroneously broken by the fingers or that the fingers may be erroneously cut by the cutting edge. Further, since the edge portion of the circular hub is sharp in shape, there is a possibility that the fingers firmly gripping the circular hub may be cut by the sharp edge portion of the circular hub. In view of these circumstances, there have been proposed various blade changing tools for changing a cutting blade. For example, Japanese Utility Model Laid-open No. Hei 7-3952 discloses a blade changing jig for easily changing a cutting blade mounted through a flange member to the front end of a spindle in a dicing device or the like.
The blade cutting jig disclosed in Japanese Utility Model Laid-open No. Hei 7-3952 is specially designed for the replacement of a ringlike cutting blade (ring blade), and does not support a hub blade. In general, a blade changing jig (blade changing tool) configured by removing a magnet from the blade changing jig disclosed in Japanese Utility Model Laid-open No. Hei 7-3952 is used in removing a hub blade or a flange with a hub.
This blade changing tool has a structure like a clothespin such that when a finger operated portion is nipped by the fingers, a blade holding portion is opened, whereas when a force applied to the finger operated portion is removed, the blade holding portion is closed by a spring to hold the blade. Accordingly, in the condition where the blade is held by the tool, a holding force cannot be applied to the tool, and there is a possibility that the blade holding portion may become unstable due to settling of the spring, for example. In addition, the degree of opening of the blade holding portion is not limited, so that there is a possibility that the tool may strike the blade in holding the blade, causing damage to the blade.